Participants under moderate stress who drank a ‘wellness beverage’ reported a better mood improvement compared to a placebo group, according to a study published in the peer-reviewed Journal of the American College of Nutrition.

Zeal Wellness​​, manufactured by Houston-based Zurvita Holdings, was the beverage studied. The company provided funding for the clinical trial.

The objective was to investigate how the beverage affects standardized measures of mood states, including overall feelings of vitality in healthy, moderately stressed adults.

“Zeal Wellness significantly improved mood states after 28 days of supplementation in moderately stressed but otherwise healthy individuals,” ​the researchers wrote in their report​​. Contract research organization KGK Science conducted the clinical trial at their Florida location.

They added: “An interesting observation was that 87% of participants were not previous dietary supplement users, suggesting that dietary supplementation with Zeal Wellness may have bridged the gap between micronutrient deficiency and emotional health.”​

Study Design: Participants and investigational beverage​

The study was a randomized double-blind, placebo-controlled parallel clinical trial conducted between December 2015 and June 2016. The study lasted four weeks with four clinic visits (beginning of trial, day 8, day 15, and day 29).

Participants were screened for ‘moderate stress’ using a stress/vitality questionnaire, and 99 participants passed the screening. They included both male and female participants aged 18 to 65 years old, body mass index 18.5 to 29.9, and were in general good health as per a laboratory test result and medical history.

The ingredients in the investigational beverage Zeal Wellness include ‘amylase-enzyme-modified’ stabilized rice bran and rice germ, fructooligosaccharide from chicory root, and caffeine from guarana seed powder.

Results: ‘Possible nutrient deficiency in the population studied’​

The participants were randomized into one of four groups: 14 g of Zeal Wellness powder once daily at breakfast; 14 g of Zeal Wellness powder twice daily at breakfast and lunch (28 g per day total); 14 g of placebo powder once daily; and 14 g of placebo powder twice daily.

They were instructed to dissolve the powder in approximately 250 mL of cold water. The placebo was matched to the investigational beverage in color, texture, flavor, and aroma to ensure blinding.

Researchers found that participants in the two-dose group reported a 6.6% decrease on the Profile of Moods-Total Mood Disturbance questionnaire, and a 6.8% decrease in the anger-hostility mood state compared to the placebo group at day 29. This section of the questionnaire asked participants about five negative mood states.

Furthermore, the two-dose Zeal Wellness group provided a 12.8% greater improvement in ‘vigor-activity,’ the positive mood state question in the survey, compared to participants who only took one dose of Zeal Wellness.

“From the results of this study, it is possible to suggest that supplementation with Zeal Wellness addressed a nonspecific nutrient deficiency in the population studied,” ​the researchers wrote.

“Assessing participant vitamin and mineral levels prior to the start of the start of the study may have provided valuable information for application in the future studies of functional beverages to be extended to populations such as the elderly, vegans, and smokers.”​